All important dates and holidays happen in Antarctica, but it depends on who is there to celebrate them.
There are no native or cultural holidays founded in Antarctic culture, because there is no Antarctic culture.
Every person who lives there does so temporarily, because their government hired them to work in support of science.
Important calendar dates for 2010 can be found at calendarlabs.com . Here you can find holidays for different countries also.
For what religion? for Christianity in general, i would say that Christmas and Easter Sunday are the two most important holidays
Governments decide which days will be designated holidays, civic or otherwise. Likewise governments, in the United States that would be specifically the United States Congress, decide if the dates of holidays, including civic ones, should be changed.
Spanish Holidays - 1921 was released on: USA: August 1921
Food Network Holidays - 2006 Happy Holidays 3-8 was released on: USA: December 2012
Antarctica - 2011 was released on: USA: 1 May 2011 (internet)
1=New years!
dates for inuit
Hope for the Holidays - 2004 TV was released on: USA: 2004
Raggs - 2006 Holidays was released on: USA: 9 April 2008
The Flipside - 2012 Holidays was released on: USA: 21 December 2012
Home for the Holidays - 2012 was released on: USA: December 2012 (internet)